Improvement in bridges



, are also made of tubes or pipes.

PAENT JOHN w. PosT, OE NEW YORK, N. Y.

IMPROVEMENT IN BRmGEs.

Specication forming part of Letters Patent N o. 176,806, dated May 2,1876; application tiled April 11, 1876.

To all whom it may concern:-

Be it known that I, JOHN W. Postr, of New York city, in the county ofNew York and State of New York, have invented certain new and usefulImprovements in Deck Truss- Bridges; and I do hereby declare that thefollowing is a full, clear, and exact description thereof, which willenable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, and toletters of reference marked thereon, which form a part ot' thisspeoication.

The object of my invention is to construct a truss-bridge of deck' formespecially adapted for railroad purposes, that is very light, strong,simple, and durable, and that can be easily taken apart and set up inthe desired locality.

This inventionv consists of a deck trussbridge constructed in all itsmain parts of pipes or tubes made of wrought or cast iron, steel, orother suitable material, and whose parts can be easily put together ortaken apart for transportation to the desired place. It also consists ina peculiarly-shaped metal tie for securing and retaining the rails inposition in a simple and effective manner, in connection with thebridge, and in making the piers or abutments of tubular or ellipticalshape braced together by tubes or pipes. 1

In the accompanying drawing, Figure 1 i a side elevation of my improvedbridge. Fig. 2 is a plan view of the same. Fig. 3 is an end view of thesame. Fig. 4 is a cross-section on line :c w of Fig. 1. r v

In the drawing, A represents the upper or main chord of a bridge, madeof` tubes or pipes, and B the lower or truss chord, which acts, in thiscase, as a tension-chord, and between which are arranged the verticalbraces or struts C and inclined braces C', which are screwed intosuitable couplings into the chords A and B, or secured in any othersuitable manner. These two trusses or girders are secured together andheld in position, according to the'width desired, by horizontalcross-braces a and b, as well as by diagonal braces c, and

In the center of the bridge is furthermore arranged a diagonalcross-brace, H, secured to the upper and lower chords A and B in anysuitable manner. The upper chords A A are, t'urthermore, held in placeby iron cross-ties D, which are of peculiar construction. They are madeof two pieces, d d, held apart by short thimbles e at their ends. Saidends are notched, and partly embrace the chords A, as best seen in Fig.3, and are recessed on their upper sides so as to embrace or grasp thelower edge ot' the railroad-rails E, and hold them firmly in theirproper position. It' desired, iiat tie-rods f may be inserted in thecenter of the crossties, or round ones in the eye g on each end of saidcross-ties, to which hand-rails may be secured. The piers or abutments FFl arel made oi' cylindrical or elliptical tubes, and with diagonalcross-braces G and struts H, also made' of tubes or pipes. The piers aresecured to the foundation by a short tube, F2, which is built into thefoundation, and held byan anchor-plate, h, and cap-plate h', which arescrewed or keyed into the tube F2, a short end oi' which protrudesthrough the cap-plate h', and over this the tubular columns ot' thepiers exactly tit, and areV secured by keys or pins c'.

In constructing the bridge, the chords B, with their struts and braces,are arranged on the lower side of the chord A, and may be secured to thepiers or abutments in any suitable manner.

The great advantages of my bridge are,

that greater strength and steadiness are ob-` tained with less and verylight material than most bridges in use; that it can be very easilyputtogetherand taken apart l'or transportation, &c.; that it can belengthened or shortened to suit different locations bythe addition andinsertion of additional lengths of tubes or pipes, which can also bevaried in size to suit diii'erent loads or strains; that it does notneed costly stone or brick abutments, and these can also be lengthenedor shortened to suit different heights, and offer very little resistanceto the water; andthat these bridges can be furnished at a veryreasonable cost, and are not likely to get out of repair.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-

1. The girder or truss herein described, con- EErcEa structed of tubularchords A B, with vertical braces or struts C and inclined braces C',substantially as shown.

2. In combination Wih a bridge, the metal crossties D, composed of theparts el d and thilnbles e, and provided with notches orv recesses forthe'reception of the railroad-rails E, when constructed substantially asshown and herein described.

3. The combination ofthe bridge herein described, consisting of tubularchords A B, vertical braces or struts C, and inclined braces C', withthe tubular piers F F1, secured by tubes F2, anchor-plates h, cap-plates it', and keys fi, all constructed and arranged as shown andspecified.

4. The bridge herein described, consisting of the upper and lower chordsA B, braces C C', cross-braces a b c, and diagonal braces H,

and the cross-ties D, all constructed substan' JOHN W. POST.

Witnesses:

J. R. NOTTINGHAM, FRED. R. GooDRrDGE.

